Advice from the clinical psychologist and parenting expert on how to help your teenage daughter deal with exclusion in secondary school and how to stop a three-year-old's temper tantrums.

Q. Our 13-year-old daughter has struggled since she started secondary. A new girl joined in with her group of friends in First Year. The other girls seemed to idolise this girl, but my daughter didn't have the same 'girl crush' (as she described it) on her. Her friends then started to leave her out (not invited to sleepovers, for example), which she was really angry about, and it ended up in a nasty confrontation on Snapchat. The summer was okay, but now she is back into class with them and worried about exclusion all over again. How can we help her?

David replies: You may not be able to help her, or at least not directly. By the time our children get into secondary school, so much more of their social arrangements are done entirely independently of us - meaning we have less opportunity to influence things, compared to when they were in primary school.

Even if we are still involved in their social lives, how our children actually cope with the interaction with friends, or potential friends, is dependent on the dynamic between them. That dynamic, in turn, is a product of each of their temperaments and their social skills.

Add, then, the dynamic of a larger group of friends and our influence on what happens is further diluted.

The best thing we can offer our children and teenagers is often just a listening ear, and if they are open to it, some worldly advice about how we might approach some of the friend dilemmas that they face. This is what I think you need to offer your daughter.

Be warm and empathetic in relation to the anxiety she feels about being left out again this year. Try not to blithely reassure her that all will be well. Given that it is a group of girls that all seem to be acting in unison, it may actually be really hard, or impossible, for your daughter to regain her place with them.

Fluidity and the ebb and flow of friendships is quite common for girls. They seem to fall into, and out of, friendships much more frequently than boys. The potential for bitchiness and establishing social hierarchies is also greater.

The new girl, who the group befriended last year, seems to have changed the dynamic of the group entirely. The fact that your daughter wasn't so besotted with her may have actually set her apart from her other friends.

I could imagine that your daughter blames this girl for messing up her friendships and so, at this stage, could have developed quite a negative reaction to her. If this girl continues to hold sway in the group, it might mean that your daughter will not be welcome unless she tries to bury the hatchet, so to speak.

Your daughter may also need a bit of advice about how she manages her Snapchat communications. Snapchat, or any other social media, is a disaster for trying to resolve conflict.

It is so hard to communicate the extra, non-verbal, elements of emotional tone and meaning in any text-based or written communication. It is easy for stuff to be misunderstood, or taken out of context.

Even though your daughter may have been justifiably angry that she was left out of a sleepover, or whatever, it seems like the Snapchat confrontation may have made things worse, since everyone took on the licence to be nastier online than they might have been in person.

Conflict is a natural and, at times, healthy part of all relationships and friendships. But, conflict is much more likely to be resolved in person, by talking, than on social media.

Perhaps your daughter needs to identify one or two of the girls in the group, who may be able to empathise with her position and talk to them. Face to face. If she can explain her feelings and let them know how hurt and frustrated she is, it may create an opportunity to heal some of the rift that has developed.

Those girls, in turn, if they can acknowledge how upsetting it is for your daughter, and if they care enough, may help to engineer a re-acceptance of you her into the group. If not, then your daughter may have to consider developing new friendships, which I am sure may be a challenge in its own right.

How do we stop our three-year-old's bedtime tantrums and help her settle to sleep easier?

Q. Our three-year-old daughter has terrible tantrums, directed at her dad, at bedtime. She has a baby sister aged six months. The causes of the tantrums are so minor, like the duvet not being the way she wants it. Offering her the chance to breastfeed used to stop the tantrums but not anymore - they usually happen at some stage during story-time or just getting into bed. She has even broken her cot-bed in her rage. The foolproof routine since birth is no longer calming or enjoyable. Please help as we are all worn out.

David replies: Any disruption to children's sleep routines takes its toll on both the child and the parents. You and your daughter are, no doubt, exhausted and emotionally on edge by the time you are going to bed. Also, if you are breastfeeding your six month old, you are probably feeding her through the night too. So, it is definitely worth trying to resolve the tantrums that your daughter is having.

You make reference to breastfeeding having a great soothing and calming effect on your older daughter up until recently. So, I presume that means that you have continued to tandem feed both girls.

I could imagine that your older daughter enjoyed the continuity, familiarity and closeness that the feeding brought, when faced with the significant change brought about by her sister's arrival.

I could imagine that having that consistency was lovely for her during the transition to big sisterhood. In theory, it will have allowed your closeness with her to continue, uninterrupted. In practice though, I wonder if that has been her experience, or your experience?

It is quite possible that your older daughter has had to wait more for her feeds, or that she still feels her little sister has been an intrusion into her life, disrupting your availability to her.

I also wonder if that disruption has insinuated itself into her bedtime routine. You mention that she gets cross with her dad, who, I presume, is the one settling her to sleep at night.

Used her dad always be the one to put her to bed? I would guess that if you have been breastfeeding her all along, that you were centrally involved in her bedtime in the past, and that breastfeeding was also a key part of that bedtime routine at some point.

Has the baby's arrival changed all of that? I would guess that it has. Could you be less available to your older daughter at bedtime now than you were in the past? If so, then your daughter may just be really frustrated and upset, missing you at this key time.

She may have accepted her dad's comfort and soothing in the early days and weeks of her sister's birth, assuming that this was only some temporary arrangement that would, in due course, revert to 'normal'. But as time has gone on, maybe she has realised that the change is here to stay and perhaps she is just protesting and displaying her reluctance to accept the change?

The nature of her tantrums, a big reaction to a relatively minor issue, does suggest that the tantrum is driven by some underlying, and as yet unresolved, frustration or upset.

Even though she is only three, it might be well worth your while talking with her about the changes that have occurred since her sister has arrived.

If you can acknowledge the positive changes and the negative changes, it may help your daughter to realise that you do 'get' that it might have been a hard and upsetting adjustment to becoming an older sibling. Alongside the opportunity to vent some of her feelings, you might want to consider swapping roles again, such that you take primary responsibility for getting your older daughter to bed and your husband settles the baby.

Again, your goal is not to make this an exclusive arrangement, but just to give your daughter enough sense that she is as important to you as her little sister. A few weeks, or a month, of 'you time' at bedtime might settle her back into her old habits, such that she can be open again to some change and you can again mix and match who puts who to bed.